OutdoorKing Repair Forum Forums Repairs and Maintenance Questions On Ride On Mowers Questions on Greenfield Ride On Mower Frames Evolution 3 Mk2A 12.5-30 Drive Idler Pulleys

I have taken my mower out of service because of a horrible bearing noise in the drive train. All of the parts diagrams I can access show that the Evo3 machines have only one set of idler pulleys in the drive belt path between the motor and the drive clutch pulleys. I looked at the IPBs for my model and ordered replacement pulleys. That didn't help because having hoist it up and getting the deck off it is apparent that my machine has TWO sets of drive belt idler pulleys - one pair mounted vertically just forward of the clutch pulleys (present on all IPBs, GT1009 for my machine), and a second pair mounted horizontally just aft of the engine. This second pair is NOT shown on any of the IPBs.
With the frame raised and the deck off it became apparent that these two unidentifed horizontal pulleys close to the engine are the source of the noise - one of them is a bit notchy/noisy and the other has frozen to the shaft, with rotation being accomodated by the mounting bolt turning with the bearing.
I'm happy to get replacement pulleys but my problem are:
1. the blind bolt heads for the retaining nuts of these pulleys are not fixed, are difficult to access and, believe it or not, have round heads.
2. the pulleys are of different size, one similar to GT1009 of the rear idler pulleys and the other being about 1cm smaller.
My question is - can I just remove these two forward idler pulleys? If they're not on any IPB then presumably they are not essential, but I can only imagine that the factory put them there for a reason. And if I do need them, how do I get replacement if i don't have a Greenfields part number?
I will provide pics once I get it up and onto its side.

Hi Matt,
I find the easiest way to work on these rideons is to stand them up vertically using a chain block.

Thanks Norm
Is that vertical lift with the front upwards?

Yes Matt

Pics of the unidentified front drive path idler pulleys:


The purpose of these pulleys appears to be to guide the drive belt straight onto the rear drive guide pulleys (those rear pulleys being found in all Evo3 IPBs, GT1009). The plate on which these front two pulleys are mounted is separated from the frame by about 1cm, and is welded on. The heads of the bolts that mount the pulleys are between the plate and the frame, and as described before have ROUND HEADS (determined by feeling in through the access slots in the side of the mount plate) so I can't slide a flat spanner in to lock them for undoing. WTF??

The IPBs and owner's manual diagrams of the drive belt path show only the rear pulleys, and it is possible that bypassing these front pulleys would have the belts approaching the rear pulleys at about 12 degrees out of alignment - see the belt path diagrams:

Mostly I'm seeking confirmation that taking out removing the front pulleys and having the drive belts go straight to the rear pullys is likely to work, even with the 12deg approach angle of the drive belt to the rear pulleys.

Cheers
Matt

Hi Matt,
I would say the belt will have to run around the pulleys, that angle will cause you problems. Are you saying you can't undo the nuts holding the idler pulleys on? If they are dome headed bolts then they should be held in a square hole in the plate. If this is what you are up against then it is going to become a dogfight. My only suggestion would be to cut the nuts off with a dremel or something similar. Once you have the pulleys off then you will have to work out how you can remount the pulleys. It can always be done, it depends on your skill level and the tools you have at your disposal

Norm,

Thanks for that. Yes, confirming that I can't undo the nuts of the front two pulleys because the shafts of the bolts rotate, and the heads of the bolts are both hidden under the plate and are round. I know of the dome-headed bolts with the square-keyed shaft that you mentioned (like some blade bolts) and no they aren't dome heads. From what I can feel the heads are about the dimensions of a normal bolt but without the flats that you'd apply a spanner to. I'm going to try making up some wedges to jam the heads with to avoid cutting. Once I get the pulleys off I'll try to drill a hole to weld the heads from from the accessible side.

That still leaves me with the problem of replacing the pulleys. Like I said above - these pulleys do not show in the IPBs and so I can't get a part number for them. And one of the pulleys is distinctly smaller than the available rear pulleys. From what I can estimate, putting a standard pulley in place of the small one would leave too small a gap to the mower side frame to get the belt in.

So, are these front pulleys a standard fit to Evo 3 mowers? If so, they should be in the IPB and there should be part numbers for them. If not, how do standard Evo 3 mowers accommodate the approach angle at the rear pulleys?

Cheers
Matt

Hi Matt,
I feel your pain, sometimes manufacturers do the dumbest things with no forethought about maintenance. I have only briefly worked on an Evo and not on the underside but what I am thinking is that they had to run the belt across to clear the steering because that is a huge improvement over the Anniversary ones, they were terrible. The Anniversary ran the belts straight from the motor because they didn't have to clear the steering. Once you get the pulleys off you will be able to see how you can replace the bearings in them, I have cut a couple open and fitted new bearings in them, but can't remember how I did it. The other alternative is to just google around looking for idler pulleys something out there will fit. doesn't have to be for a Greenfield. You might have to make up a bush, or use a bigger diameter bolt, plenty of options just a pain when you can't get a part off the shelf

Looking at the pics above the upper/fwd pulley is 3in in diameter and of V (not flat) configuration. I can't find a Greenfields v-idler pully of 3in diameter, but there is Toro one that is avaialble.
The lower/centre pully is a flat idler of the same dimensions as the GT1009 of the rear pully pair.
I'm getting to the point of desperation for getting these pulleys off - has anyone else had success in getting them off? Is there some trick to preventing the bolt shafts from turning with the nut?

I knew it was going to be hard Matt that is why I suggested cutting the heads off with a dremel with a small cutting disc. I have no idea why Greenfield did that but sometimes manufacturers do the most stupid things
Another option Matt is to cut one side of the pulley off and then you might be able to get the grinder in and gut under the pulley and cut through the bolt. Another option may be to cut down the side of the bolt and cut through the bearings, just hack and chop your way till you can end up cutting through the bolt. And if you had access to oxy you would have them off in 5 mins. Sometimes the world gives you lemons

Hi Matt & Norm,

Without seeing the round bolt heads it's difficult to know what is going on but they could be alley keyed heads.

When 2 sets of idler pulleys are used you can't just throw them over your left shoulder.


Cheers
Max.

Hi Max,
Yes I'm not even sure how they would have tightened them up because they are nylok nuts

There should be a hole on the other side of the mower frame base Norm to get an Allen key through into the bolt ,if not
I would drill a hole as the bracket could have been put together with the pulleys then the bracket was welded on.

The other 2 vertical pulleys, it may have been easier to remove the 4 bracket bolts to get the assembly out then remove the pulleys.

Cheers
Max.

Max,
Thanks, that's exactly the situation with this machine.
I'ts a shame that I didn't see your response earlier (my fault), it would have simplified things greatly.
Can you tell me the model that it came from so that I can get the manual from Greenfield and get the alignment pulley numbers to the guys who are fixing this for me?
Thanks
Matt

Hi Matt,


I just used Google and found some Greenfield images ,I'm sure it wasn't the same model as your
one and didn't see any part numbers, no records were kept for where the images came from.

You should be able to contact Greenfield with all your model details and they can look up the part numbers for you,
send some images of the parts as well if it helps them. From memory the images I found were from a mower with a
larger motor than 12.5 hp.

https://greenfield.com.au/contact/

Outdoorking may have them for sale if you contact the spare parts shop and ask

https://www.outdoorking.com.au/index.php?main_page=contact_us

Normally I would just get the dimensions from the old pulleys you need, then google Greenfield drive idler pulley
and contact the sellers that have the same looking pulleys and ask them if the dimensions are the same as what you are after before buying. some sellers are money back guarantee if the parts aren't what they say they are.



Cheers
Max

Thanks Max,

It seems like knowing the correct model was the main problem all along. Because of your diagrams I looked further forward into the Greenfields manuals available at [url=https://greenfield.com.au/manuals/][/url] and found that the closest match to the systems of my mower is an Evolution 2009 Fastcut 32.

I have attached a pic of the Belt Guide Pulley page from that manual showing the explodes parts breakdown (in usefully high resolution), the part numbers and the installation instructions.

What I find entirely bizarre is that the V Idler Pulley that I'm having most trouble with is not a single pully with bearing like the other three in the drive belt path, instead it is a large bearing with snap ring and bearing adapter, two half pulley shells and two washers with that bearing and bolt assembly rotating with the inner race of the bearing, with the outer race of the bearing mounted to the support plate by two spacer plates that hold the snap ring. That's using ten pieces to do what the other idler pulley does with five.

Anyway, now that we've got an appropriate mower model and component part numbers I should be able to make some progress.

Thanks again,

Matt

Hi Matt,


The 10 pieces is made to take a load because it's on the drive/tension side of the V belt and the five pieces
pulley is on the slack side of the V belt and not under as much load.

Good to know what manual the images I found were from as I thought the engine listed in the manual was bigger than 12.5.


Cheers
Max.

It's still not entirely clear, because my mower is definitely a 30 inch model, not 32 or 34 as per the manuals, and the serial number of the engine apparently indicates a build year of 2011.

Still, progress!

Cheers

Quick update - the machine is back together, the drive train is blissfully quiet and the transmission works smoothly again.

Big mowing done, great to have it back.

NormK - Thanks for the tip for lifting the mower front up, made much of the process simple.

Max - thanks for the access hole tip. Yes the guys fixing it did have to drill two access holes into the top of the frame body to access the hex recess in the pulley bolt heads, and had to move the steering wheel cover out of the way to do so. So, yes, it looks like Greenfield bolted these idler pulleys to their mount plate before welding the mount plate to the frame. Not helpful.

I would like to modify the thread name to correct the model designation to Evolution 2009, but I don't seem to be able to do that.

Cheers

Matt

Well done Matt, some of these jobs on rideons can be such a pain in the butt, but grass keeps growing and you have to cut it